Detected blight strain linked to Great Famine

Scientists have named a unique strain of blight which they believe triggered the Irish potato famine as HERB-1.

The famine, which saw 1 million people perish in the mid-19th century has been linked to a fungal disease called potato blight, from Mexico.

A team of molecular biologists from Europe and the United States reconstructed the spread of the potato blight pathogen from dried plants.

Many of the materials, despite being between 120 to 170 years old, contained intact pieces of DNA, according to the details published in the journal eLife.

A strain called US-1 was thought to have been the cause of the fatal outbreak, but the new study suggests a different but closely related strain may have been the cause.

Hernan Burbano from the Max Planck Institute for Developmental Biology said: “Both strains seem to have separated from each other only years before the first major outbreak in Europe.”

Potato blight is caused by the microorganism Phytophthora infestans which destroys the leaves of potato crops.

The international team of scientists looked at 11 historical samples of Phytophthora infestans from potato leaves collected over more than 50 years.

These came from Ireland, the UK, Europe and North America and had been preserved in the herbaria of the Botanical State Collection Munich and Kew Gardens in London.